Melanoma skin cancer is becoming more common among Hispanics and whites, a new study suggests.

The research also shows that among blacks and Hispanics, melanoma is likely to be diagnosed at a more advanced stage.

White people, particularly those with fair skin, have the highest rates of melanoma — the least common but most deadly form of skin cancer.

In the new study, researchers at the University of Miami focused on 41,072 Florida residents diagnosed with the disease between 1990 and 2004. As expected, most cases — more than 39,000 — were seen in non-Hispanic whites. An additional 1,148 occurred in Hispanic whites, while 254 cases occurred among black men and women.

Over the study period, melanoma rates rose by 3 to 4 percent among non-Hispanic whites and Hispanic white women. Hispanic white men showed a roughly 1-percent increase.

But while non-Hispanic whites accounted for most of the melanoma cases, the timing of their diagnoses steadily improved: at the outset, about 8 percent of patients were diagnosed only after the cancer had spread throughout the body; that figure was less than 5 percent in 2004.

In contrast, timing of diagnoses did not improve in blacks and Hispanic whites, Dr. Shasa Hu and colleagues report in the Archives of Dermatology.

The findings, they write, point to both advances and shortcomings in the battle against melanoma.

The earlier diagnoses among whites are encouraging, the researchers say, as the improvement suggests that white patients are becoming more aware of the signs of melanoma and that doctors may be doing more skin-cancer screening.

On the other hand, Hu's team writes, the increasing rates of melanoma among both non-Hispanic and Hispanic whites indicate that more needs to be done on the prevention front.

In addition, the researchers say, black and Hispanic adults — along with their doctors — need greater awareness of melanoma in general so that they can lower the risk of developing it, and be diagnosed earlier when the cancer does occur.

Over the course of the study, one-quarter of black patients and 18 percent of white Hispanics were diagnosed after their melanoma had spread, compared with 12 percent of whites.

"The results of our study," Hu's team writes, "should motivate the expansion of melanoma awareness and screening campaigns to the minority communities, which can ultimately alleviate the disparities in melanoma outcome in these populations."